From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.8 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30ADFC433DB for ; Sun, 27 Dec 2020 00:47:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1816217A0 for ; Sun, 27 Dec 2020 00:47:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726160AbgL0Aq5 (ORCPT ); Sat, 26 Dec 2020 19:46:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54736 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725834AbgL0Aq4 (ORCPT ); Sat, 26 Dec 2020 19:46:56 -0500 Received: from mail-ot1-x334.google.com (mail-ot1-x334.google.com [IPv6:2607:f8b0:4864:20::334]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E38FCC0613C1 for ; Sat, 26 Dec 2020 16:46:15 -0800 (PST) Received: by mail-ot1-x334.google.com with SMTP id r9so6341447otk.11 for ; Sat, 26 Dec 2020 16:46:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=SCcDAq1vx1rq+khgfj2C8Z6X6qgNeLzbSQZknX3MThk=; b=sy/rykXo/FRQEq0/TxDVzPDMGqgFybPLTzbWbJNL/gqnd98GstGFv+ALhsFgRy+eNZ dw2LSeN91oKxnmfWVCuGmpBfLvYrospIBbmwcI1CgFU6dMwKuhEABRhgubsOFJiu+Fvq eN1iXuUyXoOrg7JJZ3ualv6xYvwj7vl5CjaiCbqrUrvAvF8Gw6WLMFyBiw818OiFbex4 W91QV1M0kUfTcDf6vKhZJSAi6zwrQ5cpP0vd8GTq4HUvbB6E6AtCNv3kBN6aarnGlbXY /04w53yPA3slMfsLvTHRXctX6R0/6A2NqzCzqE5XZLNDm33Tt0VU6Tf023dUbCbwi2fh 6YGg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=SCcDAq1vx1rq+khgfj2C8Z6X6qgNeLzbSQZknX3MThk=; b=g50dmRCvMmZB0M6+Kpbu0lePzC52KtChgKaZX9TkBpPT4K+BKEgQnvytUNXEOxA6D/ fcIzlVDVl4VLYnOH7kJooSp1mg9R/t4RFml0KUHuzL0QgxreoHYohFGaDdHScMa0khKv NNMQb7lV7FrEAhAwMsVZe6LljknyO5517VRKsyH+7EiEGSnViHXKDXZsXhG0fyqJuOvz vlur2Ip1jIgAz9//o/7bWqUR6PAivpskIpa6Jz6/rHdnOZCfAjopGJ86qPvXt/D7dIc1 FciQOCY3MBVndXTOIMhoIn6SIcRRnMUuD7qJgZxKt6UndIzpzKccHluA3owBpnZfUR9s OVtg== X-Gm-Message-State: AOAM5332HgxB3MZiUU/NHkyVNUfLNPle+SdzkxQLmdX776d8X4akEmcW qxmiD5bVOpFqvekopIbG8uXUjGTKstgygg== X-Google-Smtp-Source: ABdhPJzwlNaCKWypZRgSBM2YuwBl7PIaMGbdjfU62eHRJZtGMdj6masRtaLILV4j6n4gjYdm1kEQlQ== X-Received: by 2002:a05:6830:114e:: with SMTP id x14mr28821611otq.253.1609029974392; Sat, 26 Dec 2020 16:46:14 -0800 (PST) Received: from eggly.attlocal.net (172-10-233-147.lightspeed.sntcca.sbcglobal.net. [172.10.233.147]) by smtp.gmail.com with ESMTPSA id t26sm8322868otm.17.2020.12.26.16.46.12 (version=TLS1 cipher=ECDHE-ECDSA-AES128-SHA bits=128/128); Sat, 26 Dec 2020 16:46:13 -0800 (PST) Date: Sat, 26 Dec 2020 16:45:55 -0800 (PST) From: Hugh Dickins X-X-Sender: hugh@eggly.anvils To: "Kirill A. Shutemov" cc: Linus Torvalds , Hugh Dickins , Matthew Wilcox , "Kirill A. Shutemov" , Will Deacon , Linux Kernel Mailing List , Linux-MM , Linux ARM , Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , Vinayak Menon , Android Kernel Team Subject: Re: [PATCH 1/2] mm: Allow architectures to request 'old' entries when prefaulting In-Reply-To: <20201226224016.dxjmordcfj75xgte@box> Message-ID: References: <20201219124103.w6isern3ywc7xbur@box> <20201222100047.p5zdb4ghagncq2oe@box> <20201225113157.e7hmluffh56fszfc@box> <20201226204335.dikqkrkezqet6oqf@box> <20201226224016.dxjmordcfj75xgte@box> User-Agent: Alpine 2.11 (LSU 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 27 Dec 2020, Kirill A. Shutemov wrote: > > Here's the fixup I have so far. It doesn't blow up immediately, but please > take a closer look. Who knows what stupid mistake I did this time. :/ It's been running fine on x86_64 for a couple of hours (but of course my testing is deficient, in not detecting the case Linus spotted). But I just thought I'd try it on i386 (hadn't tried previous versions) and this has a new disappointment: crashes when booting, in the "check if the page fault is solved" in do_fault_around(). I imagine a highmem issue with kmap of the pte address, but I'm reporting now before looking into it further (but verified that current linux.git i386 boots up fine). Maybe easily fixed: but does suggest this needs exposure in linux-next. Hugh